Cardiac Tissue Characterization and Imaging in Autoimmune Rheumatic Diseases

Inflammation, microvascular and macrovascular ischemia, valvular disease, and fibrosis are the main causes of cardiovascular disease (CVD) in autoimmune rheumatic diseases (ARDs). The silent presentation and the high mortality and/or morbidity of CVD in ARDs necessitate a reliable tool for early diagnosis. Noninvasive cardiovascular imaging, including echocardiography, nuclear imaging, cardiovascular computed tomography (CT), cardiac magnetic resonance (CMR), and hybrid imaging modalities, constitutes the main tool for monitoring of CVD in ARDs. Echocardiography is the cornerstone for CVD evaluation, but it is operator-dependent and cannot perform tissue characterization. Nuclear imaging and CT, although promising, have the disadvantage of ionizing radiation. CMR can assess inflammation, ischemia, and fibrosis without ionizing radiation, thus making it a necessary adjunct, which is especially relevant for ARDs with new-onset heart failure, conflicting data from other imaging modalities, and recent onset of chest pain and/or arrhythmias. Recently, hybrid imaging with positron emission tomography (PET)/CT and PET/CMR has shown promise in ARDs, although these modalities currently have prohibitive costs.